High antigen density of BCMA: friend or foe to CAR T cells?

The therapeutic landscape of multiple myeloma (MM) has been rapidly evolving with the development of newer modalities such as chimeric antigen receptor T-cell (CAR-T) therapies. Currently, there are two CAR-T cell products approved by the U.S. Food and Drug Administration for MM, idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel). Both products target B cell maturation antigen, or BCMA, on the surface of MM cells and showed impressive results in pivotal clinical trials, with overall response rates of 73% and 97%, respectively.1 2 Nonetheless, to date, MM remains largely incurable, with post BCMA-directed therapy relapse posing a major hurdle.